1. Field of the Invention
This invention relates to a rotation unit attachable to an insertion unit insertable into a small hole, an insertion apparatus, an insertion body, an insertion apparatus in which this insertion body is provided, and an insertion system including the insertion body and the insertion apparatus.
2. Description of the Related Art
For example, Jpn. Pat. Appln. KOKAI Publication No. 2005-329000 has disclosed a structure in which a rotation unit having a fin portion outside the distal end of an insertion portion of an endoscope and having a permanent magnet inside can be rotated if a magnetic force is applied to the rotation unit from the outside of the rotation unit. The rotation unit is provided outside a slide pipe which has a flange at the proximal end to support the end of the rotation unit. A thread portion is formed at the end of the slide pipe, and a fixing ring member is threaded into the thread portion so that the rotation unit is fixed and does not come off the slide pipe.